It has been years since most TV boxes support HDMI 2.0 4K60, but PCs with integrated GPU still doesn't support this well. In most cases, the chipsets support it, but the motherboard doesn't.
A problem of 4K30 is higher latency, which 4K60 solves. A problem of FHD is the image is not as sharp as 4K, and looks horrible on some TVs that do image processing (e.g. sharpness improvement) on non-native resolutions which may benefit videos, but will make a desktop image awful.
So, I need a DIY motherboard CPU with integrated CPU/GPU supporting RGB 4K60 over HDMI 2.0 and:
(1) Is a new platform that support DDR4 3000+
(2) Is low power, but not low performance (like the Intel Celeron N3150, for which running VM is real pain).
(3) (Optional) PCIe*8+ slots for expansion (PCIe*1 is always there).
(4) A mainstream-priced motherboard from top vendors is preferred.